Microarray analysis of therapeutic (GM4) and non therapeutic (GM) NOD DC

We have previously demonstrated that bone marrow-derived DC can prevent diabetes development and halt progression of insulitis in NOD mice, the mouse model of type 1 diabetes (T1D). The DC population that was most effective in this therapy had a mature phenotype, expressed high levels of costimulatory molecules and secreted low levels of IL-12p70. The protective DC therapy induced regulatory Th2 cells that shifted the dominant Th1 environment, present in NOD mice, to a mixed Th1/Th2 milieu. Microarray analysis of therapeutic and non-therapeutic DC populations revealed several novel molecules that could play important roles in the observed DC-mediated therapy. The therapeutic DC population expressed a unique pattern of costimulatory molecules and chemokines, which were confirmed by flow cytometry and ELISA assays. We have performed in vitro chemotaxis assays that demonstrated the therapeutic DC preferentially attracted Th2 cells, as compared to Th1, Treg or nave T cells. In addition we quantified the in vivo migration of activated islet-specific T cells to the pancreas using novel cell labeling techniques and 19F nuclear magnetic resonance. A subcutaenous injection of therapeutic DC alters the migration of both Th1 and Th2 cells to the pancreas, and Th1 cells appeared in the lymph node draining the site of DC injection. These results suggest that the therapeutic function of DC is mediated in part by the chemoattractive properties of these DC for diabetogenic Th1 cells.

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Morel PA, Srinivas M, Turner MS, Fuschiotti P, Munshi R, Bahar I, Feili-Hariri M, Ahrens ET